Electric motor housings for gasoline engine starters



' Dec. 23, 1958 MUSGRAVE 2,865,358

ELECTRIC MOTOR HOUSINGS FOR GASOLINE ENGINE STARTERS Filed June 25, 1956 5 Sheets-Sheet 1 INVENTOR ORLY MUSGRAVE.

BY ZZMi ATTORNEYS ,1958 o. MUSGRAVE 5 ELECTRIC MOTOR HOUSINGS FOR GASOLINE ENGINE STARTERS Filed June 25, 1956 3 Sheets-Sheet 2 INVEN TOR ORLY MUSGRAVE BY 714Wv 7W ATTORNEYS United States atent ELECTRIC MOTOR HOUSINGS FOR GASDLINE ENGINE STARTERS Orly Musgrave, Springfield, Ohio Application June 25, 1956, Serial No. 593,624;

3 Claims. (Cl. 123-479) This invention relates to starting apparatus for gasoline engines, and particularly to starters for gasoline engines of small horse-power, such as those gasoline engines customarily employed in lawn mower equipment.

The primary object of the invention is the proviiion of simplified starting apparatus for gasoline engines, which apparatus is capable of being mounted upon gasoline engines of commerce without substantial modificat1on of the structure of the gasoline engine.

An important object of the invention is the provision of starting apparatus for gasoline engines, which starting apparatus is of compact construction having a minimum of weight, which is economically manufactured, efficient, durable, and entirely satisfactory for the purposes for which it is designed.

A particular object of the invention is the provision of a novel housing arrangement for electric motor-driven gasoline engine starting apparatus.

Yet another object of the invention is to provide gasoline engine starting apparatus which is of improved construction and readily assembled from a few component parts, all so constructed and arranged as to preclude breakage or derangement of the same.

These and other objects and advantages will become more apparent from the following detailed description and accompanying drawings wherein:

Figure l is a perspective view of the starter apparatus of invention adapted for direct current operation and as shown arranged for mounting on a gas engine;

Figure 2 is a sectional view taken on line 2--2 of Figure I;

Figure 3 is a fragmentary view with parts broken away illustrating the cooperative relation between the starting apparatus of Figure l and the frame, shaft and flywheel of a gasoline engine;

Figure 4 is a fragmentary view, partially in section, taken substantially on line 4-4 of Figure 2;

Figure 5 is a fragmentary view, partially in section, taken substantially on line 5-5 of Figure 2 and of slightly decreased scale;

Figure dis a perspective view with parts broken away and shown in section illustrating the starting switch assembly of the starter apparatus;

Figure 7 is a bottom plan view partially in section illustrating a novel power transmission arrangement including cooperating clutch elements;

Figure 8 is a schematic view illustrating a mode of making electrical connections for the operation of the structure of Figure 2;

Figure 9 is a fragmentary view, partially in section, particularly illustrating novel structural arrangements of the motor supports and housing thereof;

Figure 10 is a view partially in section taken substantially along line.10-10 of Figure 2;

Figure 11 is an elevational view partially in section of starter apparatus for operation on alternating current; and

Figure 12 illustrates a modified arrangement of a portion of the structure of Figure 1 wherein provision is made for resiliently mounting the starting apparatus.

Referring to the drawings, the numeral 1 generally designates the housing for the starter apparatus. This housing comprises a motor mounting 2, a switch mounting 3. and a header 4.

Motor mount 2 is preferably of aluminum and cast in one piece; the mount comprises a tub-like portion 5 and a foot 6 of circular contour having bolt holes 7 and supporting webs 8.

The tub 5 has a base l1 provided (Figure 2) with a depending boss 12, which boss incorporates a vertically extending central pin-receiving aperture 13. Tub 5 is provided (Figures 2 and 10) with integral inwardly extending opposed curved wall portions 14 forming a continuation of the main wall of the tub and having an inwardly extending lip 15 which is a continuation of a lip 15a of the tub wall proper.

The base 11 is also provided with a plurality of short depending protuberances lid in the form of nipples and having lower smooth faces which serve as abutments in the aligning of the components of the apparatus as noted hereinafter.

Extending upwardly from the base 11 adjacent one end thereof (Figure 2) is an integral pedestal 17 which re ceives therein a bronze bushing 19 shouldered at 21] as shown. A narrowed down portion of electric motor shaft 21 is received for rotation in bushing 19 and the shaft is supported on shoulder 2d. Shaft 21 is provided at its lower end with gear teeth 23 formed integral with the shaft and the shaft and gear teeth pass downwardly through the base.

The numeral 25 generally designates the armature of an electric motor which is carried by shaft 21; the iron core of this motor indicated at 26 is snugly fit, preferably press fit, onto the combination of lip 15, T1542 and is itself shaped as shown in Figure 10; the core is securely retained by the circular wall of the tub (Figure 10).

The motor field coils 27" are disposed (Figure 10) on opposite sides of the iron core and are supported thereby; the coils are inwardly of the core and form closed loops in vertical planes, each coil passing from left to right at the upper end, as viewed in Figure 10.

Clamps as at 24 (Figures 2 and 10) pass over and vertically down the coils centrally and draw upper and lower portions of the coil towards each other; the core serves to abut the upper and lower portions of the coils and to permit tension by the clamps 24; thus the core carries the field coils. Two field coils 27 (Figure 10) electrically connected are provided in insulated relation with the core and closely fit the core.

The header 4 is substantially cylindrical and formed of light-weight metal such as a thin sheet steel and is provided with a spherically shaped integral portion 28 which receives a bearing 29, in which bearing the upper end of shaft 21 is supported; bearing 29 is suitably of bronze, and an oil-less, self-aligning type. An apertured metallic bearing-retaining plate Ell of thin sheet steel is spot-welded or otherwise suitably secured to the header 4.

Header d is also provided, as shown at 32, with an enlarged shirt and at 332a with a plurality of inwardly projecting serrations disposed about the periphery of the header and which abut the iron core 26 (Figure 2) to aid in retaining the core firmly mounted.

Long, headed, screw-threaded bolts 33, 34 pass upwardly through the header 4i (Figures 1 and 9') and receive nuts 35, 36, respectively, which nuts bear against washers as at 37 on the top of the header; the bolts 33, 34 at their lower ends have heads as at 35a which bear against the under-side of the base it (Figure 9) and thus retain the header and motor mounting 2 in secured relation. The bolts 33, 3 4 as shown in the drawings pass freely vertically through the iron core 26 and draw header 4, switch mount 3 and tub 2 into secured relation.

Referring now to Figures 4 and 9 particularly, the numeral 38 designates a support plate of electrically in-- sulating material and through which the bolts 33, 34 pass. Plate 38 is apertured centrally to receive therethrough commutator 39 carried on shaft 21. Plate 38 mounts brush holders 4t), 4-1 which retain, respectively, spring biased brushes 42, 43 for cooperation with the commutator (Figure 4).

Brush 42 is grounded through lead 44. secured to the bolt 33 by cooperating nuts indicated at 45 (Figure 9). Brush 43 is connected by lead 46 through terminal d7 (Figure 2) to the field coil means, as may be most clearly seen from the schematic circuit illustration in Figure 8, the lead 46 passing through (Figure 4) the late; for this purpose the plate is apertured at the terminal point and a bared portion of lead 46 is soldered to the terminal pro iding for rigidity in the connection.

Sleeve means 48 of insulating material freely slidable on the bolt 33 as indicated in Figure 9 abuts and supports the plate 38 and is itself supported from iron core 26. Similar sleeve means (not shown) on bolt 34 complete the support of the plate 38.

Referring now to Figure 2, the switch mount 3 comprises an upstanding portion 49 and a laterally extending portion 56, and the switch mount 3 positions securely and removably over the tub-like portion of the motor mount in substantially press fit relation. The upstanding portion 49 closely engages the iron core 26 around the periphery thereof.

The laterally extending portion 50 is apertured to receive a flanged metallic retainer cup '1 (Figure 6) which retains and rotatably houses plunger knob 52; plunger 52 carries a metallic stem 53 which extends downwardly through aperture 54! of cup 51. The stem 53 is adapted to project well below the cup when the plunger is moved downwardly against the action of spring 55 housed between disc 56 and the plunger at recess 57.

The stem 53 carries washers 53 of insulating material to prevent grounding through retainer cup 5'1; and at its lower end the stem is provided with a bronze backing washer 59 which fits over an element carrying a plurality of spring contacts 66. As shown (Figure 6) contacts 6t) are suitably four in number and formed from a disc which is apertured to pass onto the end of stem 53 to be retained by bent-over fingers 61 of the stem 53 (Figure 6).

Contacts 6t) are adapted to engage (Figures 5 and 6) electrical contacts or connectors 62, 63 supported on terminal board 64 mounted on fibre insulation block 35 which is secured on the upper side of base M. Contacts 62, 63 are reversely bent as shown most clearly in Figure 6 to facilitate the soldering of leads 66, 67 thereto.

Lead 67 extends from contact 63 through the mounting 3 (Figure l) and is adapted to be connected to a 6-volt battery 68 (Figure 8) one side of which battery is grounded.

Lead 66 passes from the contact 62 to field coils of the motor (Figure 8). When the spring contacts 60 are urged downwardly by force applied to the plunger 52, electrical contact is made through the stem 53 from battery 68 (Figure 8) to the motor to energize the latter. I

It is to be noted, and as most clearly seen from Figure 5, that electrical contact will be made in any rotative position of knob 52 since the spring contacts 60 span the contacts 62, 63 in any position of rotation.

Referring now to Figures 2 and 3 particularly, the

frame of a gasoline engine is indicated at 69 and the rim 6 of the starter apparatus is received thereon. The rim 6 forms a portion of the motor mounting 2 as already noted and as most clearly shown in Figures 1 and 2. Suitably the bolt holes 7 each may have a hollow resilient collared mounting (Figure 12) member 7a against which a securing bolt and nut (not shown) is adapted to bear for resilient mounting of the starter apparatus on the frame of the engine.

Meshing with the gear 23 (Figure 2) is a large gear 76 which rotates on the boss 12. The gear 70 has an upper planar face which substantially abuts against the faces of the nipple-like protuberances 16. A washer 71 is abutted by a snap ring 72, which snap ring serves to retain the gear 70 and washer 71 in supported position (Figures 2 and 7). A pin 73 of soft brass extending into the aperture 13 provides for component alignment and for limiting the upward passage of a driven assembly designated by the numeral 74 in Figure 3 and now to be described. Pin 73 is a hollow cylindrical element split longitudinally and having a degree of resilience which permits it to be snugly mounted.

Formed integral with the gear 70 and carried on the lower face thereof is a plurality of ratchet teeth which depend below the gear teeth and are radially thereof (Figure 7). These teeth form the driving component of a clutch assembly. The driven clutch assembly 74 as shown in Figure 3 is secured to the shaft 76 of the gas engine which is to be started. Shaft 76 has keyed thereto a flywheel '77; shaft 76 above the flywheel carries a cup-shaped member 78 of metal, which cup extends upwardly in close fitting engagement with a lower skirt portion 79 of the motor mounting 2. This cup-shaped member 78 inhibits the entry of dust and grit to the driving and driven components of the clutch.

Threaded onto the shaft 76 is a pawl carrying driven clutch member indicated generally at 80; member 8% pivotally carries oppositely disposed pawls 81 which are normally biased by springs 82 inwardly to the position shown in Figures 3. Nut 83 retains the threaded clutch member 80 firmly to the shaft 76; washer 8 provides the clutch member in spaced relation with cup 78, the cup bearing against the member 8d; the cup 78 is apertured and free with respect to shaft 76.

As will be noted from Figures 3 and 7, in the starting position, the pawls 81 will engage the ratchet teeth '75 and when the motor is energized rotation of the gears 23 and 70 will cause rotation of the ratchet teeth 75 and consequently of the driven assembly including the shaft 76 and flywheel 77. When the gas engine comes up to speed centrifugal force will cause the pawls d1 to be thrown outwardly free of the ratchet teeth against the actions of springs 82, and the starter motor will thus be disengaged from the gas engine in the normal operation of the structure.

Referring now to Figure 11, there is shown therein a housing which is adapted for utilization with alternating current driven motors. Corresponding components in Figure 10 are designated by the same numerals as in the prior figures, but primed.

Referring more particularly to Figure 11, the header 4- snap fits over the upstanding portion of the switch mounting 3'. It will be noted that the upstanding portion of the switch mounting 3' is somewhat shorter than the upstanding portion of the switch mounting 3, but is otherwise substantially the same.

Leftwardly in Figure 11 the laterally extending portion 5t) of the switch mount 3' is apertured and receives a flanged metallic cup 51, which is secured to the mounting proper by self-threading screws as shown. Passing inwardly of the flanged metallic cup 51' is a conduit portion 85 of a jack 86 carrying three electrically insulated spaced prongs 88, 90, 92 from which leads 94, 96, 98 extend.

Jack 86 is slidably mounted and manipulable for the insertion thereof in a suitable outlet plug for connection in the present instance of a voltage source (not shown) of 110-170 volts.

Lead 94 is grounded by connection to screw which passes through the housing as shown. The other two leads 96, 98 are secured by connectors 102, 104, re-

anemone spectively, to leads 1%, 108 which respectively pass to the field coils of the motor.

The field coils are themselves electrically connected to the brushes d2, 43 by leads 110, 112, respectively; as shown in Figures 11 lead llltl is soldered to terminal 114 carried on the terminal board or support plate 38'. Lead ms is similarly provided diametrically opposite on the terminal board. The structure of the apparatus shown in Figure 11 is otherwise similar to that shown in Figures 1 and 2.

It is to be particularly noted that the starter apparatus is adapted to be united with a gasoline engine simply by providing the driven assembly on the available end of the crankshaft '76 of the engine and then merely positioning the starter assembly as a unit over the driven assembly.

The starter apparatus is itself readily assembled and disassembled, which factors form important features of the invention. Thus in the assembly of the structure of the starting apparatus, a preferred method is to invert the motor mount 2 and to secure the combination of gear 17 and ratchet thereon by means of washer 71 and snap ring '72 (Figures 2 and 7). Thereafter the mount 21 is positioned right side up and the combination of the fibre insulating block 55 and the connector carrying terminal board (54 mounted. Also at this time the bushing w is slipped into position on the pedestal 17.

The motor unit is itself separately assembled including the core as carrying the field coils 27 with the armature inserted in the core and having the plate of insulating material 33 slipped over the shaft 21; the electrical connections, as shown in the upper portion of Figure 2 having been initially made.

This motor unit combination is then slipped into the upstanding portion 49 of the switch mount 3, which switch mount has already had the metallic retainer cup Eli and its associated parts mounted thereon.

The headed bolts 33, 34 are then supported in any suitable manner upwardly through the base 11 and the combination of the switch mount and the motor unit previously described are slipped into position over the bolts, with the shaft 21 positioned in the bushing 19.

Just prior to bringing the switch mount over the tub of the motor mount 2 electrical connection is made be tween the field coils and the terminals; such connection may be made as in Figure 11 if desired. Thereafter the header carrying the bearing 29 is secured over the upstanding portion of the switch mount, and pressed downwardly to bring the inwardly projecting serrations 32a in contact with the upper end of the core 26.

i l/hen mounting the assembled unit upon a gasoline engine, pin-receiving aperture 13 accommodates a soft brass pin '7?) to aid in vertical aignment of the driven clutch element, the pin normally abutting the nut 33 and being adapted to wear readily.

starting apparatus thus described provides a compact apparatus, economical to manufacture, having particular utility in conjunction with gasoline engines of small horsepower, for example, 2 /2 to 4 horsepower. Such engines are used extensively on small home equipment, for example, on gas and lawn mowers.

It will be understood that this invention is susceptible to modification in order to adapt it to different usages and conditions and accordingly, it is desired to comprehend such modifications within this invention as may fall within the scope of the appended claims.

I claim:

1. In combination, in electrically operable starter apparatus, a starter housing comprising a longitudinally extending tub-like casing including a base having an opening therethrough, a foot of the casing supporting the base upwardly, an electric motor having a vertically extending motor shaft journalled in the opening and passing downwardly therethrough, a switch mount in the ii form of a cover on said casing, said switch mount having an open top portion extending around said motor shaft, stationary elements of said motor including an iron core supported on an internal lip of said casing below said switch mount, a header over said open top portion of said switch mount closing the same surrounding and inclosing the motor, the upper end of said motor shaft being journaled in said header, movable elements of said motor secured on said motor shaft and retained in the combination of header, switch mount and casing, and means carried by the starter housing for connecting said motor to a source of voltage, said means including a manually manipula-ble member supported by said switch mount.

2. In combination, in electrically operable starter apparatus, a starter housing comprising a longitudinally extending tub-like casing including a base having an opening therethrough adjacent one end of the casing, a foot of the casing supporting the base upwardly, an electric motor having a vertically extending motor shaft journalled in the opening and passing downwardly therethrough, a switch mount in the form of a cover on said casing, said switch mount having an open top portion extending around said motor shaft, stationary elements of said motor including an iron core supported on an internal lip of said casing below said switch mount, a header over said open top portion of said switch mount closing the same, surrounding and inclosing the motor, the upper end of said motor shaft being journalled in said header, movable elements of said motor secured on said motor shaft and retained in the combination of header, switch mount and casing, and means carried by the starter housing for connecting said motor to a source of voltage, said means including a manually manipulable member supported by said switch mount on the end thereof opposite said open top portion of the switch mount.

3. In combination, in electrically operable starter apparatus, a starter housing comprising a longitudinally extending tub-like casing including a base having an opening therethrough, said casing having inwardly extending opposed curved wall portions forming a continuation of the main wall of the casing, said main wall and curved wall portions being provided with an inner lip circumaxial with said opening, a foot of the casing supporting the base upwardly, an electric motor having vertically extending motor shaft journalled in the opening and passing dawnwardly therethrough, a switch mount in the form of a cover on said casing, said switch mount having an open top portion extending around said motor shaft, stationary elements of said motor including an iron core fitting snugly on said internal lip of said casing below said switch mount and retained by said casing, a header over said open top portion of said switch mount closing the same, surrounding and inclo-sing the motor, the upper end of said motor shaft being journalled in said header, movable elements of said motor secured on said motor shaft and retained in the combination of header, switch mount and casing, and means carried by the starter housing for connecting said motor to a source of voltage, said latter means including a manually manipulable member.

4. In combination, in electrically operable starter apparatus, a starter housing comprising a longitudinally extending tub-like casing including a base having an opening therethrough, a foot of the casing supporting the base upwardly, an electric motor having a vertically extending motor shaft journalled in the opening and passing downwardly therethrough, a switch mount in the form of a cover on said casing, said switch mount having an open top portion extending around said motor shaft, stationary elements of said motor including an iron core supported on an internal lip of said casing below said switch mount, a header over said open top portion of said switch mount closing the same, surrounding and inclosing the motor, the upper end of said motor shaft being journalled in said header, movable elements of said motor secured on said motor shaft and retained in the combination of header, switch mount and casing, means carried by the starter housing for connecting said motor to a source of voltage, said means including a manually manipulable member supported by said switch mount, and retaining bolt means including long threaded bolts passing upwardly through said base and iron core, said means engaging said base and header and retaining said casing, header and switch mount together.

5. In combination, in electrically operable starter apparatus, a starter housing comprising a longitudinally extending tub-like casing including a base having an opening therethrough, a foot of the casing supporting the base upwardly, an electric motor having a vertically extending motor shaft journalled in the opening and passing downwardly therethrough, a switch mount in the form of a cover on said casing said switch mount having an open top portion extending around said motor shaft, stationary elements of said motor including an iron core supported on an internal lip of said casing below said switch mount, a header over said open top portion of said switch mount closing the same, surrounding and inclosing the motor, the upper end of said motor shaft being journalled in said header, movable elements of said motor secured on said motor shaft and retained in the combination of head, switch mount and casing, and means carried by the starter housing for connecting said motor to a source of voltage, said means including a three connector element jack slidingly mounted in an aperture of said switch mount.

6. In combination, in electrically operable starter appa'ratus, a starter housing comprising a longitudinally ex tending tub-like casing including a base having an opening therethrough, a foot of the casing supporting the base upwardly, an electric motor having a vertically extending motor shaft journalled in the opening and passing downwardly therethrough, a switch mount in the form of a cover on said casing, said switch mount having an open top portion extending around said motor shaft, stationary elements of said motor including an iron core supported on an internal lip of said casing below said switch mount, a header over said open top portion of said switch mount closing the same, surrounding and inclosing the motor, the upper end of said motor shaft being journalled in said header, movable elements of said motor secured on said motor shaft and retained in the combination of header, switch mount and casing, means carried by the starter housing for connecting said motor to a source of voltage, said means including terminal means on the base insulated with respect thereto and connected to said motor, and a contact carrying plunger on said switch mount cooperable with said terminal means.

7. In electrically operated starter apparatus for internal combustion engines having a frame and a crankshaft, the

combination of a starter housing on the frame over an end of the crankshaft, the housing comprising a longitudinally extending tub-like casing having a boss depending therefrom intermediate the length of the casing and an internal integral'upstanding bored pedestal adjacent one end of the casing, an electric motor including an armature shaft mounted vertically in said one end of the casing and having the armature shaft thereof removably and rotatably supported in said bored pedestal, said armature shaft extending through the bore of said pedestal below said base and carrying an integral gear on the end thereof, a larger gear rotatably mounted on said boss engageable with the motor shaft gear, overrunning clutch means positioned functionally and structurally between said larger gear and said crankshaft, a skirt on said casing around said larger gear and a cup on said crankshaft extending upwardly to said skirt around said clutch means, and means carried at the other end of the housing manipulable for connecting said electric motor to a source of voltage, said means being electrically connected internally of the housing to said motor.

8. In an electrically operated starter for internal combustion engines having a frame and a crankshaft extend ing upwardly, the combination of a starter housing on the frame, the housing having a boss depending toward the crankshaft, a gear rotatable on the boss, protuberances on the housing abutting the gear and spacing the gear from the housing, an electric motor in the housing having a motor shaft extending vertically, said shaft having an integral gear thereon passed downwardly through the housing and engaged with the gear on the boss, an overrunning clutch positioned operatively and structurally between said gear on the boss and said crankshaft, said clutch comprising a driving member carried by the gear on the boss and a driven member carried by the crankshaft, the boss having an alignment pin of a soft wearable material extending toward the driven clutch element and engageable thereby in the assembly of the starter.

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